我的解决方案：

用活动构造它（视图是可选的），使用处理程序发布它（有一些延迟，例如100ms更好）。直接调用输入管理器有时不起作用。只有在工作时才能获得“活动”。我认为这很正常。

如果您可以在通话时获取根视图组或编辑视图，只需发送它即可获得更好的结果。

public class CloseSoftKeyboardRunnable implements Runnable
{
    Activity activity;
    View view;  // for dialog will occur context getcurrentfocus == null. send a rootview to find currentfocus.

    public CloseSoftKeyboardRunnable(Activity activity, View view)
    {
        this.activity = activity;
        this.view = view;
    }

    public CloseSoftKeyboardRunnable(Activity activity)
    {
        this.activity = activity;
    }
    @Override
    public void run() {
        if (!activity.isFinishing())
        {
            InputMethodManager imm = (InputMethodManager)activity.getSystemService(Context.INPUT_METHOD_SERVICE);

            if (view == null) {
                view = activity.getCurrentFocus();
            }
            else
            {
                try {
                    view = ((ViewGroup)view).getFocusedChild();
                }
                catch ( Exception e) {}
            }

            Window window =  activity.getWindow();
            
            if (window != null)
            {
                if (view == null) {
                    try {
                        view = window.getDecorView();
                        view = ((ViewGroup)view).getFocusedChild();
                    }
                    catch ( Exception e) {}
                }

                if (view == null) {
                    view = window.getDecorView();
                }

                if (view != null) {
                    if (view instanceof EditText)
                    {
                        EditText edittext = ((EditText) view);
                        edittext.setText(edittext.getText().toString()); // reset edit text bug on some keyboards bug
                        edittext.clearFocus();
                    }

                    imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
                }
                window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
            }
        }
    }
}

如果您需要在片段中隐藏键盘，则此方法有效。

public static void hideSoftKeyboard(Context context, View view) {
    if (context != null && view != null) {
        InputMethodManager imm = (InputMethodManager) context.getSystemService(Activity.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
    }
}

对于视图，只需传入

getView() method

在Kotlin中，只需使用这两种方法来显示和隐藏键盘。

fun showKeyboard() =
    (context.getSystemService(AppCompatActivity.INPUT_METHOD_SERVICE) as? InputMethodManager)!!
        .toggleSoftInput(InputMethodManager.SHOW_FORCED, 0)

fun hideKeyboard(view: View) =
    (context.getSystemService(AppCompatActivity.INPUT_METHOD_SERVICE) as? InputMethodManager)!!
        .hideSoftInputFromWindow(view.windowToken, 0)

这里的视图是您当前的视图，

public void hideKeyboard() 
{
    if(getCurrentFocus()!=null) 
    {
        InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
        inputMethodManager.hideSoftInputFromWindow(getCurrentFocus().getWindowToken(), 0);
    }
}


public void showKeyboard(View mView) {
    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(INPUT_METHOD_SERVICE);
    mView.requestFocus();
    inputMethodManager.showSoftInput(mView, 0);
}

通过将Generic方法添加到Utility或Helper类。通过调用自己，您可以隐藏和显示键盘

fun AppCompatActivity.hideKeyboard() {
            val view = this.currentFocus
            if (view != null) {
                val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
                imm.hideSoftInputFromWindow(view.windowToken, 0)
            }
           window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN)

        }


 fun AppCompatActivity.showKeyboard() {
            val view = this.currentFocus
            if (view != null) {
                val imm = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
                imm.hideSoftInputFromWindow(view.windowToken, 0)
            }                     window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN)

        }

更新：我不知道为什么这个解决方案不再有效（我刚刚在Android 23上测试过）。请改用Saurabh Pareek的溶液。这里是：

InputMethodManager imm = (InputMethodManager) getSystemService(Activity.INPUT_METHOD_SERVICE);
//Hide:
imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0);
//Show
imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, 0);

旧答案：

//Show soft-keyboard:
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
//hide keyboard :
 getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);